Systems and methods for independent setting of cell change network control mode and notification of cell change mode for uncontrolled cells

ABSTRACT

Systems and Methods for Independent Setting of Cell Change Network Control Mode and Notification of Cell Change Mode for Uncontrolled Cells are provided. In some cases, separate behavior is specified for mobile stations in respect of uncontrolled cells. In some cases, behavior is signaled by the signaling used for normal cells, but different meaning is attributed to the signaling. In some cases, at least one further criterion is combined with the signaling for controlled cells to determine the behavior for controlled cells. In some cases, additional signaling is employed.

FIELD

The application relates cell change in wireless networks, and inparticular to notification of cell change, and network control over cellchange.

BACKGROUND

Some cells are uncontrolled in the sense that a PLMN (public land mobilenetwork) operator does not control the location and/or operation of thecell. Other cells are controlled in the sense that the operator doescontrol the both the location and operation of the cells. Examples ofuncontrolled cells include, for example, CSG (closed subscriber group)cells, cells controlled by home enode b's and home node b's. These cellsare also sometimes referred to as being “uncoordinated” in the sensethat they are not subject to normal radio/cell planning.

It is generally understood that there are many methods of performing ahandover for controlled cells. Inbound handover in this context refersto a cell change from a target cell's perspective where resources (forexample timeslots, frequency channels, scrambling codes, etc.) fortransmission and/or reception in the cell are allocated to a mobilestation in advance of the mobile station performing a cell change tothat cell, particularly in response to a request from the controller ofthe device's serving cell.

While the uncontrolled cells may be configured to use spectrum that isowned by the operator, the network operator does not have the samecontrol over uncontrolled cells as for controlled cells. Typically, thenetwork operator does not own the support structure (towers etc.), doesnot own or control the backhaul connection (e.g. Digital Subscriber Line(DSL) connections), does not know or control when a given uncontrolledcell is going to be switched on, and may not know or control thelocations of uncontrolled cells. The operator will typically still havecontrol of various parameters such as operating frequency, transmitpower, etc. if the operator owns the spectrum license.

In order to perform a handover to a target cell, controlled oruncontrolled, a MS (mobile station) typically needs to provideidentifying information relating to the target cell to the currentserving cell so that it can initiate a handover process. In particular,the current serving cell needs to be able to communicate with (possiblyvia a core network) the cell controller for the target cell. However,the current serving cell may not be aware of how to reach the cellcontroller for the target cell, particularly if the target cell is anuncontrolled cell, unless provided with explicit identificationinformation for the cell (such as a cell global identity). This makeshandover to such cells difficult. In contrast, for a controlled targetcell, it may be sufficient for the mobile station to provide the currentserving cell with information about the target cell. This does notrequire or cause the acquisition of any broadcast information from thetarget controlled cell for the serving cell to be able to reach the cellcontroller for the target controlled cell, since the serving cell orsome part of the network may be able to map other identifying featuresof the cell (such as operating frequency, scrambling code etc.) to theidentity of the target cell or its controller.

There are three modes of operation relating to mobility from a GERAN(GSM EDGE (Enhanced Data rates for GSM Evolution) Radio Access Network)cell to another (not necessarily GERAN) cell. The commanded mode isindicated in broadcast signalling (NETWORK_CONTROL_ORDER sent inSI2quater message, see 3GPP TS 44.018), but may also be signalled inpoint-to-point signalling. The commanded mode applies both in packettransfer mode and in packet idle mode. If a circuit-switched connectionis active (e.g. in a voice call), different procedures apply(approximately similar to the rules for NC2 described below, althoughhandover is the only permitted means of cell change in this case). Thethree modes are:

-   -   NC0: In this mode, cell reselection is autonomous (i.e. is        performed by the mobile without being prompted by the network).        Criteria for reselection are specified and parameters relating        to these criteria may be transmitted by the network;    -   NC2: In this mode, the mobile sends measurement reports to the        network indicating the signal strength/quality of neighbouring        cells; based on these reports, the network directs the mobile to        perform cell reselection or handover. Autonomous reselection in        this mode is not permitted; and    -   NC1: This is a hybrid of NC0 and NC2; in this mode, the mobile        station performs autonomous reselection if the appropriate        criteria are met. However, the mobile station also transmits        measurement reports to the network, allowing the network to        trigger reselection/handover as in NC2 mode.

The network may indicate that a CCN (Cell Change Notification) procedureshould be performed by a particular mobile station, or mobile stationsgenerally, in respect of certain neighbour cells or neighbour cellsusing a certain radio access technology (RAT). Typically the networkindicates that the Cell Change Notification procedure is to be performedthrough broadcast system information. However, it may also be signalledusing point-to-point signalling (e.g. in a Packet Measurement Order(PMO) message). The existing fields to indicate this include:

-   -   CCN_ACTIVE (sent in GPRS (General Packet Radio Service) Cell        Options, see 3GPP TS 44.060, applicable to GSM (Global System        for Mobile Communications) cells),    -   CCN_SUPPORTED (sent in System Information (SI) type 2quater        (SI2quater) see 3GPP TS 44.018, applicable to individual GSM        target cells),    -   3G_CCN_ACTIVE, E-UTRAN_CCN_ACTIVE (sent in SI2quater, applicable        to 3G (Third Generation, such as UMTS (Universal Mobile        Telecommunications System)) and E-UTRAN (Evolved Universal        Terrestrial Radio Access Network) cells respectively; these        indications apply on a per-RAT basis, i.e. to all target cells        of that radio access technology).

With current definitions, CCN is applicable only when the mobile stationis in packet transfer mode and in either NC0 or NC1 mode.

If, for the target cell for which reselection criteria are met, CCN isactive or enabled, then the mobile station sends a Packet Cell ChangeNotification (PCCN) message to the network identifying the selectedtarget cell before performing reselection.

Upon receiving a PCCN, the network may:

a) do nothing: after timers elapse at the mobile station, the mobilestation will continue with reselection;

b) order the mobile station to continue reselection to the selectedcell, by sending a Packet Cell Change Continue (PCCC) message; a PacketCell Change Order (PCCO) message may also be used in this case;

c) order the mobile station to perform reselection to a different cellby sending a Packet Cell Change Order (PCCO) message;

d) initiate a packet-switched handover procedure; this involves apreparation phase in which the target cell receives advance notificationof the mobile station's intended cell change, the target cell reservesresources and informs the mobile, via the serving cell, of theseresources. This approach can reduce the service interruption timeassociated with cell change.

Before sending a PCCO or PCCC indicating a cell change to a GERAN cell,the network may send neighbour cell system information to the mobilestation. This may include some or all of the system information that themobile station would otherwise need to receive in the target cell beforeestablishing packet transfer mode. One of the benefits of the CCNprocedure is to allow the mobile station to receive this informationbefore performing reselection and hence to avoid needing to receive itin the target cell, which may cause service interruption.

Before sending a packet-switched handover command where the target cellis a GSM cell, the network sends the neighbour cell system information.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the application will now be described with reference tothe attached drawings in which:

FIG. 1 is a schematic diagram of a mobile station, serving cell andtarget cell;

FIG. 2 is a block diagram of a mobile station;

FIGS. 3 to 7 are flowcharts of methods for execution by a mobile stationor cell controller.

DETAILED DESCRIPTION

It should be understood at the outset that although illustrativeimplementations of one or more embodiments of the present disclosure areprovided below, the disclosed systems and/or methods may be implementedusing any number of techniques, whether or not currently known or inexistence. The disclosure should in no way be limited to theillustrative implementations, drawings, and techniques illustratedbelow, including the exemplary designs and implementations illustratedand described herein, but may be modified within the scope of theappended claims along with their full scope of equivalents.

For the CCN mode and NC modes as currently specified, there is nospecific mention of uncontrolled cells in the specifications for CCNprocedures or the definition of NC0/NC1/NC2. It is therefore implicitthat the same procedures (for example signaling procedures specified in3GPP TS 44.060) apply for uncontrolled cells as for any other targetcell of the same RAT.

A set of modes were described in the background, namely NC0, NC1, NC2,and these related to different modes/levels of network control overmobile station cell change. These modes have been defined in respect ofcells generally with no distinction between the cells being controlledor uncontrolled. These modes are specific examples of cell changenetwork control modes. More generally, a set of cell change networkcontrol modes encompasses a set of modes featuring differing networkcontrol and/or mobile station autonomy with respect to cell reselection.The above-described set of modes {NC0, NC1 and NC2} is a specificexample of a set of cell change network control modes. The embodimentsdescribed herein are not limited to this particular set.

Similarly, the behaviour of the mobile station in terms of cell changenotification is either “CCN active” (or “CCN enabled”) in which casecell change notification is performed, or not, in which case cell changenotification is not performed. This has been defined in respect of cellsgenerally with no distinction between the cells being controlled oruncontrolled. In the description of the embodiments that follow,references to NCC (notification of cell change) mode refer generally toa mode of a mobile station in terms of whether a notification of a cellchange is required to be sent to the serving cell in advance ofperforming a cell change, in which case the NCC mode of mobile stationis NCC required mode, or is not required to be sent to the serving cellin advance of performing the cell change, in which case the NCC mode ofthe mobile station is NCC not required mode. The above-referenced CCNbehaviour is a specific example of this which is detailed, for example,in 3GPP TS 44.060, but it is to be clearly understood that uses of NCCmode described herein are not limited to CCN behaviour thus defined.

In some embodiments, a separate cell change network control mode settingis specified for uncontrolled cells, and a separate NCC mode setting isspecified for uncontrolled cells. The mode settings assignable foruncontrolled cells may be the same or different from the assignablemodes defined for controlled cells. However, this embodiment is in termsof the ultimate behaviour of the mobile station. It is not necessarythat new modes be defined, but simply that the mobile station does notapply the setting defined for controlled cells in respect ofuncontrolled cells.

More generally, an improved flexibility is provided such that at leastone of the cell change network control mode and NCC mode applicable to acategory of cell can be applied that is different from that signalled orotherwise specified already for cells of the same RAT. The “definedcategory of cell” may be based on one or more of:

-   -   whether or not the cell is a CSG cell    -   whether or not the cell is controlled by a H(e)NB    -   whether or not the cell is an uncontrolled cell    -   whether or not inbound handover to the cell is known not to be        supported    -   whether or not inbound handover to the cell is known to be        supported    -   whether or not outbound handover from the serving cell to the        target cell is known to be supported.

In the description that follows, cell controller is a generic term whichcould, for example, refer to base station controllers (BSC), radionetwork controllers (RNC) or eNodeB (eNB) or Home eNodeB; generally forthe purpose of this description, it is used to mean an entity whichcontrols the cell in some sense. For example, a cell controller might bean entity which initiates a handover preparation procedure for a mobilestation (“serving cell controller”) or which allocates resources in atarget cell as part of a handover procedure (“target cell controller”).The serving cell controller may, for example, be responsible forprocessing measurement reports, cell change notifications and similarmessages received from a mobile station and based on these (and otherimplementation-specific considerations) generating mobility commands(such as packet cell change order messages) to be transmitted to themobile station and/or initiating handover preparation. A GERAN BSS is anexample. The same entity or entities may function as a serving cellcontroller in respect of the cell when performing a serving cell roleand a target cell controller when the same cell is performing a targetcell role. A cell controller may perform the control function for one ormultiple cells. In some cases, a cell controller performs the controlfunction for one cell and is co-located with other cell components, suchas a component containing a wireless transceiver, such as a basestation. A cell controller may be a part of a BSS (base stationsubsystem) which includes the transceiver. References to a cell sendingor receiving something refer to a wireless transceiver sending orreceiving something, possibly under control of the cell controller ofthe cell.

Referring to FIG. 1, shown is a schematic diagram in which a mobilestation 10 has a wireless connection to a serving cell transceiver 12within serving cell 13. Also shown is a serving cell controller 14,target cell transceiver 15 within target cell 17, and target cellcontroller 16. Of course, other network elements may be present, such ascore network elements 18 and other cell controllers 20. The core networkelements may, for example, include one or more of an SGSN (serving GPRSsupport node), MSC (mobile switching centre), MME (mobility managemententity). The signalling over the air interface (between a transceiverand a mobile station) is typically performed at the RLC (radio linkcontrol)/MAC (medium access control) layer. Signalling between a BSS andcore network is separate from RLC/MAC.

The serving cell controller 14 is configured with a mobility controlunit 30 that enables the serving cell controller to perform one or acombination of two or more of the serving cell controller methodsdescribed herein.

The mobility control unit 30 may be implemented in hardware, or softwarerunning on a processing platform such as a processor or combination ofprocessors, or a combination of hardware and software. The mobilitycontrol unit 30 may be implemented as part of/a change to anothercomponent forming part of a serving cell controller. The serving cellcontroller 14 includes other components (not shown) to allow it toperform the serving cell controller functionality.

The target cell controller 16 is configured with an inbound mobilitycontroller 32 that enables the target cell controller to perform one ora combination of two or more of the target cell controller methodsdescribed herein. The inbound mobility controller 32 may be implementedin hardware, or software running on a processing platform such as aprocessor or combination of processors, or a combination of hardware andsoftware. The inbound mobility controller 32 may be implemented as partof/a change to another component forming part of a target cellcontroller. The target cell controller 16 includes other components (notshown) to allow it to perform the target cell controller functionality.

A cell controller may be implemented that includes both the mobilitycontrol unit 30 and the inbound mobility controller 32.

The mobile station 10 has at least one antenna 20, and at least onewireless access radio 22. In addition, them mobile station is configuredwith a cell change controller 24 that enables the mobile station toperform one or a combination of two or more of the mobile stationmethods described herein. The cell change controller 24 may beimplemented in hardware, or software running on a processing platformsuch as a processor or combination of processors, or a combination ofhardware and software. The cell change controller 24 may be implementedas part of/a change to another component forming part of a mobilestation. The mobile station 10 includes other components (not shown) toallow it to perform mobile station functionality.

Various embodiments that comprise methods implemented by a mobilestation or cell controller will now be described with reference to FIGS.3 to 7. For each method, unless clearly necessary for the method tofunction, it is not necessary that the steps be executed in the sequencedepicted or described.

FIG. 3 is a flowchart of a method for execution by a mobile station. Themethod involves, while in packet transfer mode, performing a firstbehaviour with respect to NCC (notification of cell change) mode andcell change network control in response to signalling of NCC mode andcell change network control in respect of some cells of a given RAT(radio access technology) (3-1); notwithstanding the signalling of NCCmode and cell change network control in respect of some cells of a givenRAT, performing a second behaviour with respect to NCC mode and cellchange network control in respect of cells of a defined category ofcells of the given RAT that differs from the first behaviour in somemanner (3-2). In some embodiments, block 3-2 applies while in packettransfer mode. Many of the other embodiments described below may beconsidered as specific examples of the method of FIG. 3; specifically,the so-called “second behaviour” is the behaviour defined for theseother embodiments in respect of cells of the defined category of cells.

FIG. 4 is a flowchart of a method for execution by a serving cellcontroller. The method involves transmitting at least one indication tosignal a desired behaviour in respect of some cells in terms of at leastone of: NCC mode and cell change network control mode (block 4-1);transmitting at least one further indication to signal a desiredbehaviour in respect of a defined category of cells in terms of at leastone of: NCC mode and cell change network control mode (block 4-2).

FIG. 5 is a flowchart of a method for execution by a mobile station. Themethod involves receiving at least one indication to signal a desiredbehaviour in respect of some cells in terms of at least one of: NCC modeand cell change network control mode (block 5-1); receiving at least onefurther indication to signal a desired behaviour in respect of a definedcategory of cells in terms of at least one of: NCC mode and cell changenetwork control mode (block 5-2).

FIG. 6 is a flowchart of a method for execution by a mobile station. Themethod involves receiving at least one indication to signal a desiredbehaviour in respect of some cells in terms of at least one of: NCC modeand cell change network control mode (block 6-1); determining a desiredbehaviour in respect of a defined category of cells in terms of at leastone of NCC mode and cell change network control mode based on at leastone of the indications sent for some cells in combination with at leastone other criterion (block 6-2).

FIG. 7 is a flowchart of a method for execution by a mobile station. Themethod involves determining a desired behaviour in respect of a definedcategory of cells in terms of at least one of NCC mode and cell changenetwork control mode based at least in part upon whether the mobilestation has previously sent a notification of cell change (block 7-1).

Further embodiments provide computer readable media having computerexecutable instructions stored thereon, that when executed by anappropriate processing device, such as a mobile device or a cellcontroller, execute any one or more of the methods described herein.

Detailed examples of the above-described methods will now be described.The examples provided below provide for the definition of thenotification/configuration of the NCC mode and cell change networkcontrol mode for a defined category of cells (such as uncontrolledcells) as opposed to NCC mode and cell change network control mode forother cells (for example controlled cells). In some embodiments,respective notification/configurations of the NCC mode and cell changenetwork control mode are defined for each of a plurality of differentcategories of cells.

Specification of Differing Behaviour for Mobile Station in Respect of aDefined Category of Cells

In some embodiments, the behaviour of the mobile station is differentfor a defined category of cells, than for other cells of the same RATthrough specification of the mobile station. For such embodiments, ingeneral, the mobile station is configured to perform a first behaviourin respect of NCC mode and cell change network control in response tosignalling of NCC required mode and cell change network control inrespect of some cells of a given RAT. In addition, notwithstanding thesignalling of NCC required mode and cell change network control inrespect of some cells of a given RAT, the mobile station performs asecond behaviour in respect of NCC mode and cell change network controlin respect of cells of a defined category of cells of the given RAT thatdiffers from the first behaviour in some manner. Various specificexamples follow.

In some embodiments, the mobile station is configured to never enter NCCrequired mode, nor to send a notification of cell change mode in respectof a defined category of cells for a given RAT, such as uncontrolledcells, notwithstanding the NCC mode or cell change network control modedefined for cells of the same RAT.

In some embodiments, for a defined category of cells, the mobile stationis configured to obey the NCC mode signalled for other cells of the sameRAT. For autonomous reselection, the mobile station is configured toperform in a defined manner, for example so as to allow autonomousreselection, irrespective of the cell change network control modesignalled for other cells.

In some embodiments, for a defined category of cells, the mobile stationis configured to obey the cell change network control mode signalled forother cells of the same RAT. For NCC mode, the mobile station isconfigured to be behave in a defined manner, for example so as to alwayssend an NCC (or never to send an NCC), irrespective of the NCC modesignalled for other cells.

In some embodiments, for a defined category of cells, the signallingtransmitted for other cells is used (one or both of NCC mode and cellchange network control). However, the behaviour specified by thesignalling is different in respect of cells of the defined category thanfor other cells.

In some embodiments, the second behaviour involves, for a definedcategory of cells of a given RAT, performing at least one of autonomousreselection and notification of cell change notwithstanding one or bothof signalled NCC required mode and cell change network control for somecells of the given RAT.

Explicit Signalling

In some embodiments, new indications are defined to explicitly signal adesired behaviour in terms of notification of cell change, and/or cellchange network control mode. These indications may be transmitted aspart of broadcast system information, or may be transmitted point topoint. In some embodiments, a separate indication for each of NCC modeand cell change network control mode is used. In some embodiments asingle indication conveys both NCC mode and cell change network controlmode. These indications may be broadcast, for example through systeminformation, or may be transmitted point to point. In some embodiments,at least one indication is sent that is further to indication(s) sentfor other cells to signal a desired behaviour in respect of some cellsin terms of at least one of NCC mode; and cell change network controlmode.

In a first specific example, a first new field is defined to indicate acell change network control mode applicable for the defined category ofcells. In another example, a second new field is defined to indicatewhether NCC is required for the defined category of cells. One or bothof the first new field and the second new field may be implemented. Insome embodiments, a single field indicates both the cell change networkcontrol mode and the NCC mode for the defined category of cells.

In a specific example, for the cell change network control mode, a newfield is referred to as “NC_MODE_CSG_E-UTRAN” in the detailed examplebelow that might be defined for target E-UTRAN uncontrolled cells. Inanother example, a new field is defined to indicate whether NCC isrequired for target E-UTRAN uncontrolled cells. In some embodiments, afield or fields similar to those defined above are defined for UTRANuncontrolled cells.

Implicit Signalling

In some embodiments, the desired behaviour in respect of a definedcategory of cells in terms of notification of cell change, and/or cellchange network control mode is implicitly signalled, for example, basedon a combination of other fields/capabilities. This signalling may bebroadcast, for example through system information, or may be transmittedpoint to point.

In some embodiments, the NCC mode and cell change network control modefor a defined category of cells (such as uncontrolled cells) isdetermined as a function of the indications of NCC mode and cell changenetwork notification mode for other cells (such as controlled cells) incombination with at least one other criterion. The at least one othercriterion may, for example, involve the transmission of a furtherindication that is specific to the defined category of cells, orcapabilities of the serving cell and/or target cell controllers (such asBSS, HeNB, HNB) to name a few specific examples.

In a first example, the desired cell change network control mode and NCCmode for the defined category of cells is based on the currentapplicable cell change network control mode for controlled cells and/orthe current NCC mode applicable for other cells (for example controlledcells) in combination with whether or not the serving cell controllersupports handover to cells of the defined category, or more generally incombination with whether or not handover from the serving cell to cellsof the defined category is supported by the network, where “network”refers to any appropriate entity other than the mobile station. The MSmay learn the behaviour of the current serving cell in this regard, forexample by means of broadcast system information, or point-to-pointsignaling (e.g. in PACKET MEASUREMENT ORDER messages) or both.

A second example which is specific to the above-described NC0, NC1 andNC2 cell change network control modes and CCN behaviour will now bedescribed. The desired cell change network control mode for uncontrolledcells is defined to be the same as the current applicable cell changenetwork control mode for controlled cells if the current cell changenetwork control mode is NC0 or NC1. Where the cell change networkcontrol mode for controlled cells is NC2, another new field is employed(example is “CSG_NC2” defined in detail below), which specifies how themobile station is to behave in respect of uncontrolled cells if NC2 isapplicable for controlled cells. In a particular example, the new fieldselectively indicates one of:

-   -   NC2 is never applicable to uncontrolled cells, and the MS should        apply NC1 behaviour (with CCN active) in respect of uncontrolled        cells—e.g. set new field to “0” to signal this;    -   rules for NC2 that apply to controlled cells also apply also to        uncontrolled cells—e.g. set new field to “1” to signal this.

In another example, a new field (referred to as “CSG_CCN” in thedetailed example below) is used to specify how the mobile station is tobehave in respect of a defined category of cells if notification of cellchange is required for other cells. In a particular example, the newfield selectively indicates one of:

-   -   notification of cell change is never applicable for a defined        category of cells (e.g. uncontrolled cells of a particular RAT),        and if in a mode that allows automonous cell change (for example        NC0/NC1) to a cell of the defined set of cells and in packet        transfer mode, the mobile station may perform autonomous        reselection to a cell of the defined category of cells without        sending a notification of cell change regardless of the whether        cell change notification is required for other cells (for        example controlled cells)—e.g. new field set to “0”,    -   the rules and indicators for notification of cell change that        apply to other cells (for example controlled cells) apply also        to the cells of the defined type—e.g. new field set to “1”.        NCCS Mode

NCCS (NCC (notification of cell change) sent) mode refers to a mode orstate of a mobile station after having sent a notification of cellchange. In a specific example, after having sent a PCCN, a mobilestation is referred to as being in “CCN mode”. In some embodiments, thebehaviour of the mobile station in terms of NCC and/or cell changenetwork control is also a function of whether the mobile station is inNCCS mode. As above, the behaviour may be defined to be different fordifferent defined categories of cells considering one or both of thecategory of the currently considered target cell and the category of thecell in respect of which the NCC was sent. For example, the behaviourdefined for CSG cells while in NCCS mode for a non-CSG cell may bedefined differently to behaviour defined for 2G cells while in NCCS modefor a 3G cell.

NCC Mode and Cell Change Network Control Mode Subject to Support forHandover

In some embodiments, the behaviour, in terms of the possibility toperform autonomous reselection and whether such reselection is to benotified in advance to the network, may also take account of whetherthere is handover support with respect to the serving cell and/or thetarget cell. Mechanisms for learning whether handover is supported inrespect of a target cell are provided in co-pending U.S. applicationSer. No. 12/690,803 filed the same day as this application, entitled“Systems and Methods For Informing Serving Cell of Target Cell HandoverCapability” (52404-287) hereby incorporated by reference in itsentirety. For example, if packet switched handover is known not to bepossible (because either or both of the serving cell controller andtarget cell controller do not support the feature), then the mobilestation may be permitted to perform autonomous reselection to the targetcell without sending a notification to the serving cell, regardless ofcell change network control mode, and whether or not notification ofcell change is required for other cells, for example even when in a cellchange network control mode that otherwise prohibits such autonomousreselection and/or when in NCC required mode.

The approaches described may provide more flexibility for the operatorin terms of controlling mobility towards controlled and uncontrolledcells, potentially taking into account the different mobility mechanismssupported for controlled and uncontrolled target cells. The approachesmay reduce signalling, for example of PCCN, PCCO/PCCC, and/or delay whennetwork behaviour would otherwise be to always accept a proposed cellchange towards a uncontrolled cell. The approaches may avoid unnecessarysignalling in the case where handover is not possible.

First Set of Examples

Network Behaviour—Inform Mobile Station Whether to Notify Serving Cellof Cell Change

A first parameter is used to indicate whether a mobile station shouldnotify the serving cell controller of a cell change prior to performingthe cell change (for example through a cell change notificationprocedure, for example to enter CCN mode) for cells, for example, of agiven RAT. The first parameter applies to cells other than cells of adefined category (or categories) unless otherwise indicated by thesecond parameter introduced below. Examples of defined categoriesinclude uncontrolled cells; 3G CSG cells; E-UTRAN CSG cells.

A second parameter is used to indicate whether the first parameter alsoapplies to cells of the defined category.

The parameters introduced above may be sent as part of systeminformation broadcast to all mobile stations, or as part of a mobilestation specific message.

Network Behaviour—Inform Mobile Station of Cell Change Network Controlfor a Defined Category of Cells

The following two paragraphs are about cell change network control mode.This may control both measurement reporting and whether autonomousreselection is permitted. If it is permitted, then the CCN mode settingindicates whether it is required to notify the network in such case.

In some embodiments, a first parameter is used to request a mobilestation to send measurement reports in respect of a set of cells, forexample controlled cells of, for example, a given RAT. A secondparameter is sent to indicate whether the first parameter also appliesto cells of a defined category of the given RAT, for exampleuncontrolled cells.

In some embodiments, if the second parameter is set to a first value,then the first parameter applies to target cells of the definedcategory, and the mobile station sends measurement reports accordingly.If the second parameter is set to a second value, then the mobilestation performs autonomous reselection to cells of the definedcategory, and does not include measurements of these cells inmeasurement reports.

Mobile Station Behaviour

Upon receiving a parameter(s) that indicate to the mobile station tonotify the serving cell of a cell change for an uncontrolled cell, themobile station performs such notification, although other criteria mayalso be imposed.

Detailed Example

The following is a detailed implementation example of the networkbehaviour introduced above.

A message, such as an SI2quater message may also contain the3G_CCN_ACTIVE parameter in order to indicate whether the MS shallperform the CCN procedures in the serving cell when re-selecting to a 3Gneighbour cell, see 3GPP TS 44.060. In some embodiments, the3G_CCN_ACTIVE parameter is used to indicate if CCN is activated inserving cell towards 3G neighbour cells other than those known to be CSGcells; it applies also to 3G CSG cells if indicated by the3G_CSG_CCN_ACTIVE parameter.

The SI2quater message may also contain the E-UTRAN_CCN_ACTIVE parameterin order to indicate whether the MS shall perform the CCN procedures inthe serving cell when re-selecting to an E-UTRAN neighbour cell, see3GPP TS 44.060.

In some embodiments, the E-UTRAN_CCN_ACTIVE parameter is used toindicate if CCN is activated in the serving cell towards E-UTRANneighbour cells other than those known to be CSG cells; it applies alsoto E-UTRAN CSG cells if indicated by the EUTRAN_CSG_CCN_ACTIVEparameter.

The following is a specific example format of the fields introducedabove:

-   -   <3G_CSG_CCN_ACTIVE: bit>    -   <3G_CSG_NETWORK_CONTROL: bit>;    -   <EUTRAN_CSG_CCN_ACTIVE: bit>    -   <EUTRAN_CSG_NETWORK_CONTROL: bit>;        and the following is a specific example of the contents of the        fields:

-   3G_CSG_CCN_ACTIVE (1 bit field)

If set to ‘1’, then {CCN is enabled towards 3G CSG cells and/or the3G_CCN_ACTIVE field applies also to 3G CSG cells}. If set to ‘0’ thenCCN is disabled towards 3G CSG cells.

-   3G_CSG_NETWORK_CONTROL (1 bit field)

If set to ‘1’, the NETWORK_CONTROL_ORDER parameter applies in respect of3G CSG cells.

-   EUTRAN_CSG_CCN_ACTIVE (1 bit field)

If set to ‘1’, then {CCN is enabled towards E-UTRAN CSG cells and/or theE-UTRAN_CCN_ACTIVE field applies also to E-UTRAN CSG cells}. If set to‘0’ then CCN is disabled towards E-UTRAN CSG cells.

-   EUTRAN_CSG_NETWORK_CONTROL (1 bit field)

If set to ‘1’, the NETWORK_CONTROL_ORDER parameter applies in respect ofE-UTRAN CSG cells.

Detailed Example

The following is a detailed implementation example of the mobile stationbehaviour introduced above.

A mobile station, which has CCN Enabled (a specific example of NCCrequired), can enter CCN Mode (CCN mode being the mode of a mobilestation that has transmitted a PCCN). The mobile station shall enableCCN when the following criteria are fulfilled:

-   -   the mobile station is camping on a cell (see 3GPP TS 45.008);        and    -   the network indicates CCN ACTIVE/3G CCN ACTIVE/E-UTRAN CCN        ACTIVE either in system information to all mobile stations in        the cell or in an individual order to a certain mobile station;        and    -   if the target cell is known to be a 3G CSG cell (respectively        E-UTRAN CSG cell), the network indicates 3G_CSG_CCN_ACTIVE        (respectively EUTRAN_CSG_CCN_ACTIVE either in system information        to all mobile stations in the cell or in an individual order to        the mobile station; and    -   the mobile station is neither in dedicated mode nor Dual        Transfer Mode; and    -   the mobile station is in NC0 or in NC1 mode for the target cell;        and    -   the mobile station is in Packet Transfer mode.

The CCN procedures and the criteria for entering and leaving CCN modeare specified in sub-clauses 8.8.2 and 8.8.3. of 3GPP TS 44.060.

Detailed Example—Network Controlled Cell Re-selection

The network may request measurement reports from the mobile station andcontrol its cell re-selection. This is indicated by the parameterNETWORK_CONTROL_ORDER. The meaning of the different parameter values isspecified as follows:

-   -   NC0 Normal MS control        -   The MS shall perform autonomous cell re-selection.    -   NC1 MS control with measurement reports        -   The MS shall send measurement reports to the network as            defined in subclause 10.1.4.1.        -   The MS shall perform autonomous cell re-selection.    -   NC2 Network control        -   The MS shall send measurement reports to the network as            defined in subclause 10.1.4.1.        -   The MS shall only perform autonomous cell re-selection when            the reselection is triggered by a downlink signalling            failure as defined in subclause 6.5 or a random access            failure as defined in 3GPP TS 44.018 and 3GPP TS 44.060 or            if the cell is barred or the C1 criterion falls below zero.            The MS shall only determine whether the cell is barred once            camped on the cell.    -   RESET The MS shall return to the broadcast parameters. Only sent        on PCCCH or PACCH.

The parameter values NC1 and NC2 only apply in GMM Ready state (A/Gbmode) or RRC-Cell_Shared state (Iu mode). In GMM Standby state (A/Gbmode) or RRC-Idle mode or RRC-GRA_PCH state (Iu mode), the MS shallalways use normal MS control independent of the ordered NC mode.

A set of measurement reporting parameters (includingNETWORK_CONTROL_ORDER) is broadcast on BCCH and, excepting E-UTRANparameters, on PBCCH if it exists. This set of parameters may also besent individually to an MS on PACCH or, excepting E-UTRAN parameters, onPCCCH in:

-   -   a PACKET MEASUREMENT ORDER message, in which case it overrides        the NC parameters broadcast in the serving cell. These        individual parameters are only valid in the serving cell.    -   a PACKET CELL CHANGE ORDER message, in which case it overrides        the NC parameters broadcast in the target cell. These individual        parameters are only valid in the target cell.

The individual parameters are valid until the RESET command is sent tothe MS or there is a downlink signalling failure or a random accessfailure or if the cell is barred or the C1 criterion falls below zero orthe MS goes to the GMM Standby state (A/Gb mode) or RRC-Idle mode orRRC-GRA_PCH state (Iu mode) or MS enters dedicated mode (A/Gb mode) orRRC-Cell_Dedicated state (Iu mode). Before the MS has acquired NCparameters when entering a new cell, the MS shall assume mode NC0 unlessNC0, NC1 or NC2 mode was explicitly commanded by a PACKET CELL CHANGEORDER message in the previous cell.

All signalling for support of network controlled cell re-selection andmeasurement reports are defined in 3GPP TS 44.060.

If the MS operates in NC2 mode, the following rules shall be applied:

-   -   The network controls the measurements of UTRAN cells by the        parameter Qsearch_P. The network controls the measurements of        E-UTRAN cells by the parameter Qsearch_P_E-UTRAN.    -   The network may control UTRAN measurements per individual UTRAN        frequency by the parameters Measurement_Control_UTRAN and        E-UTRAN measurements per individual E-UTRAN frequency by the        parameters Measurement_Control_E-UTRAN.

The NETWORK_CONTROL_ORDER parameter applies to reselection to E-UTRAN(respectively 3G) CSG cells only if EUTRAN_CSG_NETWORK_CONTROL(respectively 3G_CSG_NETWORK_CONTROL) is set to ‘1’. IfEUTRAN_CSG_NETWORK_CONTROL (respectively 3G_CSG_NETWORK_CONTROL) is setto ‘0’, then the mobile station shall behave as if in NC0 in respect ofE-UTRAN (respectively 3G) CSG cells i.e.

-   -   the MS may perform autonomous reselection to these cells        (subject to the rules applicable to CCN, if enabled);    -   the MS shall not include measurements of these cells in any        measurement reports;    -   the MS shall enter CCN mode in respect of these cells if all        other conditions are met (see 3GPP TS 44.060).        Second Set of Examples

In some embodiments, the mobile station does not enter CCN mode if thetarget cell is known to be a cell of a defined category, such as anuncontrolled cell.

CCN Mode

A mobile station, which has CCN Enabled, can enter CCN Mode, CCN modebeing a state or mode of operation of the mobile station upon havingsent a PCCN.

The mobile station shall enable CCN when the following criteria arefulfilled:

-   -   the mobile station is camping on a cell (see 3GPP TS 45.008);        and    -   the network indicates CCN ACTIVE/3G CCN ACTIVE/E-UTRAN CCN        ACTIVE either in system information to all mobile stations in        the cell or in an individual order to a certain mobile station;        and    -   the mobile station is neither in dedicated mode nor Dual        Transfer Mode; and    -   the mobile station is in NC0 or in NC1 mode; and    -   the mobile station is in Packet Transfer mode; and,    -   the target cell is not known to be a CSG cell.        Third Set of Implementation Examples        A) Network Informs Mobile Station Whether Automomous Selection        to Cells of Defined Category while in NCC Sent Mode

NCCS (NCC sent) mode refers to a mode or state of a mobile station afterhaving sent a NCC. In a specific example, after having sent a PCCN, amobile station is referred to as being in “CCN mode”. In someembodiments, the network sends a parameter to the mobile station toindicate to the mobile station whether autonomous selection to a cell ofa defined category while in NCCS mode is permitted. A detailed exampleof this approach is provided below.

B) Cell Selection and Re-selection to Cells of Defined Category

In some embodiments, if the strongest cell (as suitably defined, see3GPP TS 25.304 and 3GPP TS 36.304 for an example definition of thestrongest cell) which the MS has detected on a given frequency of a RAT(for example UTRAN or E-UTRAN) is a suitable cell of a defined category(for example, an uncontrolled cell, for example a suitable CSG cell—see3GPP TS 25.304 and 3GPP TS 36.304 for an example of suitability criteriafor UTRAN and E-UTRAN CSG cells respectively), the mobile stationreselects to the cell if it is not in NCCS mode or is not prohibitedfrom performing autonomous reselection to such while in NCCS mode, forexample due to having received from the network the above-introducedparameter that indicates to the mobile station whether autonomousselection to a cell of a defined category while in NCCS mode ispermitted, for example by an appropriate setting of the CCN_CSG_RESELparameter introduced below. A detailed example of this approach isprovided below.

C) Cell Change Notification Procedure

In some embodiments, while in NCCS mode the mobile station continues adata transfer and stores neighbour cell system information if received,for example in instances of a PACKET NEIGHBOUR CELL DATA message.However, the mobile station does not perform any cell change to a cellof a defined category (for example an uncontrolled cell, for example aCSG cell) unless autonomous cell changes to such cells during NCCS modeare permitted, for example due to having received from the network theabove-introduced parameter that indicates to the mobile station whetherautonomous selection to a cell of a defined category while in NCCS modeis permitted, for example by an appropriate setting of the CCN_CSG_RESELparameter introduced below. In this case, the mobile station may send afurther notification of cell change (for example a PCCN) indicating thetarget cell, leave NCCS mode and perform the cell change. A detailedexample of this approach is provided below. If such reselection occurs,the MS may stop any applicable timers and leave NCCS mode.

Combinations of Behaviours

In some embodiments one of the behaviours A), B), C) is implemented. Insome embodiments two of the behaviours A), B), C) are implemented. Insome embodiments all of the behaviours A), B), C) are implemented.

Network Informs Mobile Station Whether Automomous Selection to Cells ofDefined Category while in NCCS Mode is Permitted—Detailed Example

A detailed example follows in terms of additions to the SI 2quater RestOctets defined, for example, in 3GPP TS 44.060 v.9.2.0, 3GPP TS 45.008v.9.1.0, or 3GPP TS 44.018 v.9.3.0. Only excerpts are shown. The addedparameter is referred to as CCN_CSG_RESEL. A similar parameter may beimplemented in another message for CSG cells, or for another category ofcells.

10.5.2.33b SI 2quater Rest Octets

The SI 2quater Rest Octets information element contains neighbour celllists for UTRAN and/or E-UTRAN cells and/or CSG cells. For cellreselection to UTRAN, it is used with the SI 2ter Rest Octetsinformation to build the 3G Cell Reselection list, see sub-clause3.4.1.2.1.7. For cell reselection to E-UTRAN, it is used directly tobuild the E-UTRAN Neighbour Cell list.

The SI 2quater Rest Octets information element is a type 5 informationelement with 20 octet length. The following field is included:

-   <CCN_CSG_RESEL: bit>    in the message, defined as follows:-   CCN_CSG_RESEL (1 bit field): If this bit is set to ‘1’, autonomous    reselection to CSG cells is permitted while in CCN mode (see 3GPP TS    44.060). If set to ‘0’, autonomous reselection to CSG cells is not    permitted while in CCN mode.    Cell Selection and Re-selection to Cells of Defined    Category—Detailed Example

The following is a specific example implementation of the above method.

Cell Re-selection to CSG cells

If a mobile station is a member of at least one Closed Subscriber Group,i.e. at least one CSG ID is included in the MS's “CSG Whitelist”, then,in addition to normal cell reselection, the MS shall use an autonomoussearch function for UTRAN and/or E-UTRAN CSG cells.

-   -   NOTE 1: The autonomous search function is implementation        dependent and controls when and/or where to search for allowed        CSG cells.    -   NOTE 1a: The autonomous search function should take into account        previously visited allowed CSG cells.    -   NOTE 2: A cell is a CSG cell if the CSG Indicator in its system        information is set to TRUE.    -   NOTE 2a: A cell for which the CSG Indicator in its system        information is set to FALSE but broadcasts a CSG ID is        considered by the MS as a CSG cell if its CSG ID matches any of        the CSG IDs included in the MS's “CSG Whitelist”, otherwise it        is considered as a non-CSG cell towards which normal cell        reselection applies.

If the strongest cell (see 3GPP TS 25.304 and 3GPP TS 36.304 for thedefinition of the strongest cell) which the MS has detected on a UTRANor E-UTRAN frequency is a suitable CSG cell (see 3GPP TS 25.304 and 3GPPTS 36.304 for suitability criteria for UTRAN and E-UTRAN CSG cellsrespectively), it should reselect to this cell if it is not currently inCCN mode or is not prohibited from performing autonomous reselection toCSG cells while in CCN mode (see 3GPP TS 44.060).

Cell Change Notification—Detailed Example

Cell Change Notification Procedure

If CCN is enabled towards the target cell (see sub-clause 5.5.1.1a and3GPP TS 44.160), the mobile station shall behave as in network controlmode NC0 or NC1 up to the point when a new cell has been chosen. If thetarget cell is a GSM cell, the mobile station shall then check theCCN_SUPPORTED parameter, if available, that was last received for thatcell. This parameter can be sent on BCCH or PBCCH or individually inPACKET MEASUREMENT ORDER or PACKET CELL CHANGE ORDER or PS HANDOVERCOMMAND messages.

If for a GSM cell the CCN_SUPPORTED parameter is available and if itindicates that CCN mode shall not be entered towards that cell, then themobile station shall perform the cell change and not enter CCN mode. Ifthe cell reselection is triggered by the path loss criterion parameterC1 becoming negative, the mobile station may perform the cell changewithout entering the CCN mode.

If the target cell is a GSM cell and the CCN_SUPPORTED parameter isavailable and if it indicates that CCN mode shall be entered towardsthat cell or if the CCN_SUPPORTED parameter is not available, theninstead of performing the cell change, the mobile station shall starttimer T3206 and enter the CCN mode. At the first possible opportunity,the MS shall then, when in CCN mode, inform the network about theproposed target cell by sending a PACKET CELL CHANGE NOTIFICATIONmessage, stop timer T3206, start timers T3208 and T3210.

If the target cell is a 3G cell and if CCN is activated towards 3G cellsor if the target cell is an E-UTRAN cell and the mobile station supports“CCN towards E-UTRAN, E-UTRAN Neighbour Cell measurement reporting andNetwork controlled cell reselection to E-UTRAN” and if CCN is activatedtowards E-UTRAN cells, then instead of performing the cell change, themobile station shall start timer T3206 and enter the CCN mode. At thefirst possible opportunity, the MS shall then, when in CCN mode, informthe network about the proposed target cell by sending a PACKET CELLCHANGE NOTIFICATION message, stop timer T3206, start timers T3208 andT3210.

If the target cell is a GAN cell and the CCN_SUPPORTED parameter isavailable and if it indicates that CCN mode shall be entered towardsthat cell or if the CCN_SUPPORTED parameter is not available, theninstead of performing the cell change, the mobile station shall starttimer T3206 and enter the CCN mode. At the first possible opportunity, amobile station may, when in CCN mode, send a PACKET CELL CHANGENOTIFICATION message that includes the ARFCN/BSIC for the GAN cell andindicates an RXLEV of 63 for the GAN cell and start timers T3208 andT3210.

The PACKET CELL CHANGE NOTIFICATION message shall contain the identityof the proposed target cell.

In CCN mode the mobile station shall continue the data transfer andstore neighbour cell system information if received in instances of thePACKET NEIGHBOUR CELL DATA message, but not perform any cell changeunless autonomous cell changes to CSG cells during CCN mode arepermitted (see CCN_CSG_RESEL parameter in 3GPP TS 44.018), in which casethe mobile station shall send a further PACKET CELL CHANGE NOTIFICATIONindicating a target CSG cell, leave CCN mode and perform the cellchange.

The mobile station shall leave CCN mode when either CCN is no longerenabled (towards all GSM, 3G or E-UTRAN neighbour cells with theCCN_ACTIVE/3G_CCN_ACTIVE/E-UTRAN_CCN_ACTIVE bit or towards the cell thathad been re-selected) or when the network has responded with a PACKETCELL CHANGE CONTINUE or PACKET CELL CHANGE ORDER message or a PSHANDOVER COMMAND message or when either of the timers T3206 or T3208have expired or on reselection to a CSG cell (if permitted).

If the mobile station has been individually ordered to enable CCN, theorder is only valid within the cell where the order is given. When acell change has been performed using the cell reselection procedure, themobile station shall use CCN in the new cell only if individuallyordered in the previous cell with the PACKET CELL CHANGE ORDER messageor if individually ordered or broadcast in the new cell. When a cellchange has been performed using the PS handover procedure, the mobilestation shall enable CCN in the new cell only if individually ordered inthe previous cell with the PS HANDOVER COMMAND message or ifindividually ordered or broadcast in the new cell.

If the cell reselection criteria have changed during the time the MS isin CCN mode but the path loss criterion parameter C1 remains positive,the MS shall, without notifying the network about the new preferredcell, remain in CCN mode until the criteria for CCN mode are no longerfulfilled, unless otherwise specified above. When leaving CCN mode theMS shall obey the new criteria according to the normal rules asspecified in sub-clause 5.5.1.1 and 3GPP TS 44.160 and in 3GPP TS 45.008unless a PACKET CELL CHANGE ORDER or a PS HANDOVER COMMAND message hasbeen received (see bullet 3 above). If the path loss criterion parameterC1 becomes negative while the MS is in CCN mode, the MS may leave theCCN mode without notifying the network and perform the cell change.

Configure Lack of Response to Packet Cell Change Notification toIndicate Reselection not Allowed

A packet cell change notification is a message from a mobile station toa serving cell indicating that the mobile station is about to perform acell change. If the packet cell change is not permitted, in someembodiments, by not responding to the packet cell change notification,the serving cell indicates to the mobile station that the reselection isnot permitted. In some embodiments, the mobile station is configured totreat the absence of a response to a packet cell change notification asan indication that the mobile station may not perform its intendedreselection. In some embodiments such a configuration only applies for aparticular type of cells, such as uncontrolled cells, or a particulartype of uncontrolled cells. This approach may be applied to PCCN (PacketCell Change Notification) such as defined in 3GPP TS 44.060, but moregenerally may be defined to apply to any message whose purpose is tonotify the serving cell of a packet cell change.

New Message to Indicate Reselection not Allowed

In some embodiments, a new message (the Packet Cell Change Prohibitedmessage defined in detail below) is defined to indicate explicitly thatthe desired reselection (as indicated by, for example, a packet cellchange notification message sent by the device) is not permitted. Anexample message format example is provided below. The message may, forexample, be sent on a PACCH (packet associated control channel). In someembodiments, the message is a distribution message in the sense thatthat all mobile stations which receive it should process it and obey therestriction. In this case, the message may identify a particular cell towhich the restriction applies. Alternatively, the message can be mobilestation-specific, in which case it may not be necessary to identify theindividual cell to which the message applies as the mobile station willbe aware of the cell.

In some embodiments, when a mobile station receives such a message inresponse to a packet cell change notification, the mobile station doesnot perform autonomous reselection to the cell indicated in the packetcell change notification or to any other cells (if any) indicated in themessage.

In some embodiments, where a message is sent to indicate that thedesired reselection is not permitted, further information is added tothe message. One or more of the following mechanisms may be provided:

-   a) In some embodiments, the message includes an indication of    whether the restriction applies to all potential target cells (i.e.    autonomous reselection is completely prohibited) in which case the    mobile station is not permitted to send any further packet cell    change notification message while the restriction applies.-   b) In some embodiments, the message includes an indication that the    restriction applies to a particular subset of cells (e.g.    uncontrolled cells, CSG cells, non-CSG cells, cells using a    particular RAT, operating on a particular frequency, or any    combination of these). In such cases, notwithstanding the    restriction, the mobile may send a packet cell change notification    for a controlled cell. In a specific example, cells are classified    by CSG/non-CSG and by RAT.-   c) In some embodiments, the message includes an indication that the    restriction applies only to the indicated cell. In this case, the    mobile may send a packet cell change notification for any other    cell.    Timers to Prevent Multiple Packet Cell Change Notifications    Indicating the Same Cell

In some embodiments, a timer is used to prevent the mobile station fromsending a packet cell change notification indicating the same cell for atime period after a previous indication was made, and not permitted, asdetermined from one of the above mechanisms for example. The timer maystart either when the packet cell change notification was sent, or whenthe mobile station determined that the cell change was not permitted;different time limits may apply depending on the method used to preventreselection. In some embodiments, a field representing a value for thetimer is included in the packet cell change prohibited message. In someembodiments, a default timer value is applied when none is specified inthe message.

In some embodiments, different time limits are applied depending on thenumber of previously sent packet cell change notifications for that cell(e.g. shorter times for initial transmissions, longer times forsubsequent transmissions) to account for the possibility that an initialtransmission was not received correctly by the network.

Detailed Example

The following is a specific detailed example of the above-describedapproach, in terms of changes (underlined) to 3GPP TS 44.060 Sub-clause8.8.3 Cell Change Notification procedure.

3GPP TS 44.060 Sub-clause 8.8.3 Cell Change Notification Procedure

After receiving a PACKET CELL CHANGE NOTIFICATION message from themobile station the network can behave in different ways as describedbelow:

-   -   1) The network responds with a PACKET CELL CHANGE CONTINUE        message.        -   If a mobile station as response to a PACKET CELL CHANGE            NOTIFICATION message receives a PACKET CELL CHANGE CONTINUE            message without receiving any neighbour cell system            information, the mobile station shall stop timer T3208, stop            timer T3210 if still running, leave CCN mode and continue            cell reselection in NC0/NC1 mode.    -   2) The network sends first necessary system information for the        cell proposed in the PACKET CELL CHANGE NOTIFICATION message if        the proposed target cell is a GSM cell in one or more instances        of the PACKET NEIGHBOUR CELL DATA message and sends then a        PACKET CELL CHANGE CONTINUE message.        -   The mobile station shall store the received system            information as specified in sub-clause 8.8.1. When the first            instance of the PACKET NEIGHBOUR CELL DATA message is            received, the mobile station shall stop timer T3210 if still            running When the PACKET CELL CHANGE CONTINUE message is            received, the mobile station shall stop timer T3208, leave            CCN mode and continue the cell reselection in NC0/NC1 mode            irrespective of the cell indicated in the ARFCN and BSIC            parameters in the PACKET CELL CHANGE CONTINUE message.    -   3) The network sends first necessary system information for the        cell proposed in the PACKET CELL CHANGE NOTIFICATION message if        the proposed target cell is a GSM cell, or for any other GSM        cell, in one or more instances of the PACKET NEIGHBOUR CELL DATA        message and sends then a PACKET CELL CHANGE ORDER message or a        PS HANDOVER COMMAND message.        -   The mobile station shall store the received system            information as specified in sub-clause 8.8.1. When the first            instance of the PACKET NEIGHBOUR CELL DATA message is            received, the mobile station shall stop timer T3210 if still            running When the PACKET CELL CHANGE ORDER message is            received, the mobile station shall stop timer T3208, leave            CCN mode and follow the procedures as specified for the            PACKET CELL CHANGE ORDER message (sub-clause 8.4) and in            sub-clause 8.8.1. When the PS HANDOVER COMMAND message is            received, the mobile station shall stop timer T3208, leave            CCN mode and follow the procedures as specified for the PS            HANDOVER COMMAND message in sub-clause 8.10.4.    -   4) The network orders the mobile station into NC2 mode.        -   A mobile station may in response to a PACKET CELL CHANGE            NOTIFICATION message receive a PACKET MEASUREMENT ORDER            message from the network indicating NC2 mode. When the            mobile station receives the NC2 order it shall leave CCN            mode, stop timer T3208, stop timer T3210 if still running,            and go into NC2 mode.        -   When the NC2 mode has been ordered, the network may send            PACKET NEIGHBOUR CELL DATA messages on the PACCH before            sending the PACKET CELL CHANGE ORDER message to the mobile            station. When the NC2 mode has been ordered, the network            shall send PACKET NEIGHBOUR CELL DATA messages on the PACCH            before sending the PS HANDOVER COMMAND message (see            sub-clause 8.10.2) to the mobile station except if these            messages are not needed by the mobile station (i.e. for the            case of PS handover to a GAN cell).    -   5) No network response        -   When timer T3210 expires, the mobile station shall            retransmit once the PACKET CELL CHANGE NOTIFICATION message            at the first possible opportunity.        -   When timer T3208 expires, the mobile station shall leave CCN            mode and continue cell reselection in NC0/NC1 mode as            described in sub-clause 5.5.1.1 and 3GPP TS 44.160 and in            3GPP TS 45.008.    -   6) Reject the proposed cell change        -   A mobile station may in response to a PACKET CELL CHANGE            NOTIFICATION message receive a PACKET CELL CHANGE PROHIBITED            message. When the mobile station receives this message, it            shall leave CCN mode (CCN mode being the mode the mobile is            in once it has determined to perform reselection & has sent            a PCCN message) stop timer T3208, and stop timer T3210 if            running The mobile station shall not perform autonomous            reselection to the cell indicated in the PACKET CELL CHANGE            NOTIFICATION or to any other cells indicated in the PACKET            CELL CHANGE PROHIBITED message, nor send a further PACKET            CELL CHANGE NOTIFICATION message in respect of these cells            for the period indicated in the PACKET CELL CHANGE            PROHIBITED message (or for some default time, for example            30s, if no such period is indicated) after the PACKET CELL            CHANGE PROHIBITED MESSAGE has been received.            11.2.2b Packet Cell Change Prohibited

This message is sent on the PACCH by the network to the mobile stationto command the mobile station not to continue the cell reselectionprocedure.

-   -   Message type: PACKET CELL CHANGE PROHIBITED    -   Direction: network to mobile station    -   Classification: non-distribution message

TABLE 11.2.2b.1 PACKET CELL CHANGE PROHIBITED message content < PacketCell Change Prohibited message content > ::=  < PAGE_MODE : bit (2) >  { 0 < GLOBAL_TFI : Global TFI IE >    { 0 | 1 < RESTRICTION_DURATION :bit (2) > }    < RESTRICTED_RAT : bit (3) >    < RESTRICTED_RAT_CSG :bit (2) >    { 1 { 0 < CSG_FDD_UARFCN : bit    (14) > | 1 <CSG_TDD_UARFCN : bit (14) > } } ** 0    { 1 < CSG_EARFCN : bit (16) > }** 0    < padding bits >    ! < Non-distribution part error : bit (*) =< no string > > }   ! < Address information part error : bit (*) = < nostring > > }  ! < Distribution part error : bit (*) = < no string > > ;

TABLE 11.2.2a.2 PACKET CELL CHANGE PROHIBITED information elementdetails PAGE_MODE (2 bit field) This field is defined in sub-clause12.20. Global TFI This information element contains the TFI of themobile station's downlink TBF or uplink TBF. This field is defined insub-clause 12.10. RESTRICTION_DURATION (2 bit field) This indicates theduration for which the restriction applies. Bit 2 1 0 0  5 seconds 0 120 seconds 1 0 40 seconds 1 1 indefinitely (while camped on the servingcell) RESTRICTED_RAT (3 bit field) This indicates radio accesstechnologies of cells (CSG and non- CSG) to which the restrictionapplies. If a bit is set to ‘1’, the restriction applies to all cells(CSG and non-CSG) of that radio access technology. Bit 3 GERAN 2 3G(UMTS) 1 E-UTRAN RESTRICTED_RAT_CSG (2 bit field) This indicates radioaccess technologies of CSG cells to which the restriction applies. If abit is set to ‘1’, the restriction applies to all CSG cells of thatradio access technology. Bit 2 3G (UMTS) 1 E-UTRAN CSG_FDD_UARFCNCSG_TDD_UARFCN These fields, if present, indicate that the restrictionapplies to CSG cells on the indicated UTRAN frequencies. These fieldsare formatted as a UARFCN as defined in 3GPP TS 25.101. CSG_EARFCN Thesefields, if present, indicate that the restriction applies to CSG cellson the indicated E-UTRAN frequencies. These fields are formatted as forthe E-UTRA Absolute Radio Frequency Channel Number as defined in 3GPP TS36.104.

Referring now to FIG. 2, shown is a block diagram of another mobilestation 100 that is configured to perform one or a combination of themobile station implemented methods described in this disclosure. Themobile station 100 is shown with a cell change controller 101 forimplementing features similar to those of the cell change controller 24of the mobile station 10 of FIG. 1. It is to be understood that themobile station 100 is shown with very specific details for exemplarypurposes only.

A processing device (a microprocessor 128) is shown schematically ascoupled between a keyboard 114 and a display 126. The microprocessor 128controls operation of the display 126, as well as overall operation ofthe mobile station 100, in response to actuation of keys on the keyboard114 by a user.

The mobile station 100 has a housing that may be elongated vertically,or may take on other sizes and shapes (including clamshell housingstructures). The keyboard 114 may include a mode selection key, or otherhardware or software for switching between text entry and telephonyentry.

In addition to the microprocessor 128, other parts of the mobile station100 are shown schematically. These include: a communications subsystem170; a short-range communications subsystem 102; the keyboard 114 andthe display 126, along with other input/output devices including a setof LEDs 104, a set of auxiliary I/O devices 106, a serial port 108, aspeaker 111 and a microphone 112; as well as memory devices including aflash memory 116 and a Random Access Memory (RAM) 118; and various otherdevice subsystems 120. The mobile station 100 may have a battery 121 topower the active elements of the mobile station 100. The mobile station100 is in some embodiments a two-way radio frequency (RF) communicationdevice having voice and data communication capabilities. In addition,the mobile station 100 in some embodiments has the capability tocommunicate with other computer systems via the Internet.

Operating system software executed by the microprocessor 128 is in someembodiments stored in a persistent store, such as the flash memory 116,but may be stored in other types of memory devices, such as a read onlymemory (ROM) or similar storage element. In addition, system software,specific device applications, or parts thereof, may be temporarilyloaded into a volatile store, such as the RAM 118. Communication signalsreceived by the mobile station 100 may also be stored to the RAM 118.

The microprocessor 128, in addition to its operating system functions,enables execution of software applications on the mobile station 100. Apredetermined set of software applications that control basic deviceoperations, such as a voice communications module 130A and a datacommunications module 130B, may be installed on the mobile station 100during manufacture. In addition, a personal information manager (PIM)application module 130C may also be installed on the mobile station 100during manufacture. The PIM application is in some embodiments capableof organizing and managing data items, such as e-mail, calendar events,voice mails, appointments, and task items. The PIM application is alsoin some embodiments capable of sending and receiving data items via awireless network 110. In some embodiments, the data items managed by thePIM application are seamlessly integrated, synchronized and updated viathe wireless network 110 with the device user's corresponding data itemsstored or associated with a host computer system. As well, additionalsoftware modules, illustrated as another software module 130N, may beinstalled during manufacture.

Communication functions, including data and voice communications, areperformed through the communication subsystem 170, and possibly throughthe short-range communications subsystem 102. The communicationsubsystem 170 includes a receiver 150, a transmitter 152 and one or moreantennas, illustrated as a receive antenna 154 and a transmit antenna156. In addition, the communication subsystem 170 also includes aprocessing module, such as a digital signal processor (DSP) 158, andlocal oscillators (LOs) 160. The specific design and implementation ofthe communication subsystem 170 is dependent upon the communicationnetwork in which the mobile station 100 is intended to operate. Forexample, the communication subsystem 170 of the mobile station 100 maybe designed to operate with the Mobitex™, DataTAC™ or General PacketRadio Service (GPRS) mobile data communication networks and alsodesigned to operate with any of a variety of voice communicationnetworks, such as Advanced Mobile Phone Service (AMPS), Time DivisionMultiple Access (TDMA), Code Division Multiple Access (CDMA), PersonalCommunications Service (PCS), Global System for Mobile Communications(GSM), etc. Examples of CDMA include 1× and 1×EV-DO. The communicationsubsystem 170 may also be designed to operate with an 802.11 Wi-Finetwork, and/or an 802.16 WiMAX network. Other types of data and voicenetworks, both separate and integrated, may also be utilized with themobile station 100.

Network access may vary depending upon the type of communication system.For example, in the Mobitex™ and DataTAC™ networks, mobile stations areregistered on the network using a unique Personal Identification Number(PIN) associated with each device. In GPRS networks, however, networkaccess is typically associated with a subscriber or user of a device. AGPRS device therefore typically has a subscriber identity module,commonly referred to as a Subscriber Identity Module (SIM) card, inorder to operate on a GPRS network.

When network registration or activation procedures have been completed,the mobile station 100 may send and receive communication signals overthe communication network 110. Signals received from the communicationnetwork 110 by the receive antenna 154 are routed to the receiver 150,which provides for signal amplification, frequency down conversion,filtering, channel selection, etc., and may also provide analog todigital conversion. Analog-to-digital conversion of the received signalallows the DSP 158 to perform more complex communication functions, suchas demodulation and decoding. In a similar manner, signals to betransmitted to the network 110 are processed (e.g., modulated andencoded) by the DSP 158 and are then provided to the transmitter 152 fordigital to analog conversion, frequency up conversion, filtering,amplification and transmission to the communication network 110 (ornetworks) via the transmit antenna 156.

In addition to processing communication signals, the DSP 158 providesfor control of the receiver 150 and the transmitter 152. For example,gains applied to communication signals in the receiver 150 and thetransmitter 152 may be adaptively controlled through automatic gaincontrol algorithms implemented in the DSP 158.

In a data communication mode, a received signal, such as a text messageor web page download, is processed by the communication subsystem 170and is input to the microprocessor 128. The received signal is thenfurther processed by the microprocessor 128 for an output to the display126, or alternatively to some other auxiliary I/O devices 106. A deviceuser may also compose data items, such as e-mail messages, using thekeyboard 114 and/or some other auxiliary I/O device 106, such as atouchpad, a rocker switch, a thumb-wheel, or some other type of inputdevice. The composed data items may then be transmitted over thecommunication network 110 via the communication subsystem 170.

In a voice communication mode, overall operation of the device issubstantially similar to the data communication mode, except thatreceived signals are output to a speaker 111, and signals fortransmission are generated by a microphone 112. Alternative voice oraudio I/O subsystems, such as a voice message recording subsystem, mayalso be implemented on the mobile station 100. In addition, the display126 may also be utilized in voice communication mode, for example, todisplay the identity of a calling party, the duration of a voice call,or other voice call related information.

The short-range communications subsystem 102 enables communicationbetween the mobile station 100 and other proximate systems or devices,which need not necessarily be similar devices. For example, the shortrange communications subsystem may include an infrared device andassociated circuits and components, or a Bluetooth™ communication moduleto provide for communication with similarly-enabled systems and devices.

Those skilled in the art will recognize that a mobile device maysometimes be treated as a combination of a separate ME (mobileequipment) device and an associated removable memory module.Accordingly, for purpose of the present disclosure, the terms “mobiledevice” and “communications device” are each treated as representativeof both ME devices alone as well as the combinations of ME devices withremovable memory modules as applicable.

Also, note that a communication device might be capable of operating inmultiple modes such that it can engage in both CS (Circuit-Switched) aswell as PS (Packet-Switched) communications, and can transit from onemode of communications to another mode of communications without loss ofcontinuity. Other implementations are possible.

Some of the embodiments described can be implemented in the context ofone or more of the following standards, all of which are incorporated byreference in their entirety:

-   -   3GPP TS 44.060 (latest version is v.9.2.0) “General Packet Radio        Service (GPRS); Mobile Station (MS)-Base Station System (BSS)        interface; Radio Link Control/Medium Access Control (RLC/MAC)        protocol”.    -   3GPP TS 45.008: “Radio subsystem link control”. (latest version        is v.9.1.0)    -   3GPP TS 44.018 “Mobile radio interface layer 3 specification;        Radio Resource Control Protocol”. (latest version is 9.3.0)    -   3GPP TS 48.008 “Mobile Switching Centre-Base Station System        (MSC-BSS) interface; Layer 3 specification” (latest version is        9.1.0)    -   3GPP TS 43.129 Packed-switched handover for GERAN A/Gb mode;        Stage 2 (defines Handover Preparation; latest version is 9.0.0)    -   3GPP TS 48.018 “General Packet Radio Service (GPRS); Base        Station System (BSS)—Serving GPRS Support Node (SGSN); BSS GPRS        protocol (BSSGP)” (more PS Handover stuff; latest version is        9.0.0)

Numerous modifications and variations of the present disclosure arepossible in light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the disclosuremay be practiced otherwise than as specifically described herein.

1. A method for a mobile station, the method comprising: performing afirst behaviour with respect to NCC (notification of cell change) modeand cell change network control in response to signalling of NCC modeand cell change network control in respect of some cells of a given RAT(radio access technology); notwithstanding the signalling of NCC modeand cell change network control in respect of some cells of a given RAT,performing a second behaviour with respect to NCC mode and cell changenetwork control in respect of cells of a defined category of cells ofthe given RAT that differs from the first behaviour in some manner. 2.The method of claim 1 wherein the second behaviour is such that themobile station is configured to never enter NCC required mode in respectof cells of the defined category of cells, nor to send a notification ofcell change mode in respect of cells of the defined category of cells.3. The method of claim 1 wherein the first and second behaviours aresuch that: for the defined category of cells, the mobile station isconfigured to obey the NCC mode signalled for the other cells; forautonomous reselection, the mobile station is configured to perform in adefined manner in respect of cells of the defined category of cells,irrespective of the cell change network control mode signalled for theother cells.
 4. The method of claim 3 wherein the defined manner allowsfor autonomous reselection to cells of the defined category of cells. 5.The method of claim 1 wherein the first and second behaviours are suchthat: for the defined category of cells, the mobile station isconfigured to obey the cell change network control mode signalled forthe other cells; for NCC mode in respect of the defined category ofcells, the mobile station is configured to be behave in a defined mannerirrespective of the NCC mode signalled for the other cells.
 6. Themethod of claim 1 wherein the first and second behaviours are such that:the signalling transmitted for the other cells is also used to determinethe behavior for cells of the defined category of cells; the methodcomprising: the mobile station implementing the first behaviour inresponse to the signalling in respect of other cells; the mobile stationimplementing the second behaviour in response to the signalling inrespect of the cells of the defined category of cells.
 7. The method ofclaim 1 wherein the second behaviour comprises: for a defined categoryof cells of a given RAT, performing at least one of autonomousreselection and notification of cell change notwithstanding one or bothof signalled NCC required mode and cell change network control for somecells of the given RAT.
 8. The method of claim 7 wherein: the definedcategory of cells is CSG cells; the method further comprising: receivingan indication that in NC2 mode, CCN is permitted for CSG cells.
 9. Themethod of claim 1 comprising: receiving at least one indication tosignal the first behaviour; receiving at least one further indication tosignal the second behaviour.
 10. The method of claim 9 wherein the atleast one further indication comprises at least one of: a field toindicate a cell change network control mode applicable for the definedcategory of cells; a field to indicate whether NCC is required for thedefined category of cells; a field to indicate whether NCC is requiredfor the defined category of cells which is distinct from a field toindicate a cell change network control mode applicable for the definedcategory of cells.
 11. The method of claim 9 wherein: determining thedesired behaviour in respect of the defined category of cells in termsof at least one of NCC mode and cell change network control mode as afunction of at least one further indication sent for the definedcategory of cells and at least one indication for some cells.
 12. Themethod of claim 1 comprising: receiving at least one indication tosignal the first behaviour; determining the second behaviour in respectof a defined category of cells in terms of at least one of NCC mode andcell change network control mode based on at least one of theindications sent for some cells in combination with at least one othercriterion.
 13. The method of claim 12 wherein the at least one othercriterion comprises whether there is support for handover indicated bythe serving cell controller.
 14. The method of claim 12 wherein the atleast one other criterion comprises whether there is support forhandover in respect of a target cell.
 15. A method for a serving cellcontroller comprising: transmitting at least one indication to signal adesired behaviour in respect of some cells in terms of at least one of:NCC mode; and cell change network control mode; transmitting at leastone further indication to signal a desired behaviour in respect of adefined category of cells collectively in terms of at least one of: NCCmode; and cell change network control mode.
 16. The method of claim 15wherein the at least one further indication comprises at least one of: afield to indicate a cell change network control mode applicable for thedefined category of cells; a field to indicate whether NCC is requiredfor the defined category of cells; and a field to indicate whether NCCis required for the defined category of cells that is distinct from afield to indicate a cell change network control mode applicable for thedefined category of cells.
 17. The method of claim 15 wherein: whereinthe desired behaviour in respect of the defined category of cells interms of at least one of NCC mode and cell change network control modeis determined as a function of the at least one further indication sentfor the defined category of cells and at least one indication for somecells.